<template>
  <view>
    <!-- 使用自定义搜索组件 -->
    <my-search @click="gotoSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧滑动区 -->
      <scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
        <block v-for="(item, index) in cateList" :key="index">
          <view :class="['left-scroll-view-item', index == active ? 'active' : '']" @click="activeChanged(index)">{{item.cat_name}}</view>
        </block>
      </scroll-view>
      <!-- 右侧滑动区 -->
      <scroll-view scroll-y="true" :style="{height: wh + 'px'}" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2, index2) in cateLevel2" :key="index2">
          <!-- 二级分类的标题 -->
          <view class="cate-lv2-title">
            /{{item2.cat_name}}/
          </view>
          <view class="cate-lv3-list">
            <!-- 三级分类的item项 -->
            <view class="cate-lv3-item" v-for="(item3, index3) in item2.children" :key="index3" @click="gotoGoodsList(item3)">
              <!-- 三级分类的图片 -->
              <image :src="item3.cat_icon">
                <text>{{item3.cat_name}}</text>
              </image>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'
  export default {
    mixins: [badgeMix],
    data() {
      return {
        // 当前设备的高度
        wh: 0,
        cateList: [],
        // 默认的激活项
        active: 0,
        // 这是二级分类的列表
        cateLevel2: [],
        // 滚动条距离顶部的距离
        scrollTop: 0
      }
    },
    methods: {
      // 获取分类列表的数据
      async getCateList() {
        const { data: res } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message
        // 给二级分类赋值
       this.cateLevel2  = res.message[0].children
      },
      activeChanged(index) {
        this.active = index
        // 重新为二级分类赋值
        this.cateLevel2 = this.cateList[index].children
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      // 跳转到商品列表页面
      gotoGoodsList(item) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item.cat_id
        })
      },
      gotoSearch() {
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
    },
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight - 50
      this.getCateList()
    }
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;
}
.left-scroll-view {
  width: 120upx;
}
.left-scroll-view-item {
  background-color: #F7F7F7;
  line-height: 60px;
  text-align: center;
  font-size: 12px;
  &.active {
    background-color: #FFFFFF;
    position: relative;
    
    &::before {
      content: ' ';
      display: block;
      width: 3px;
      height: 30px;
      background-color: #C00000;
      position: absolute;
      top: 50%;
      left: 0;
      transform: translateY(-50%);
    }
  }
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;
  .cate-lv3-item {
    width: 33.3%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    margin-bottom: 10px;
    
    image {
      width: 60px;
      height: 60px;
    }
    text {
      font-size: 12px;
    }
  }
}
</style>
